Sir William de Montacute ^{1 2 3}

   Another name for William was John Montague.

  Research Notes:

From Reifsnyder-Gillam Ancestry, p. 51 :

"IV. LADY ELIZABETH FITZ ALAN, was born 1376, and died 8 Jul 1425. She married, first, before 1 December 1378, William de Montacute, son of William Earl of Salisbury, who died 6 August, 1383. "
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From Wikipedia - William Montacute, 2nd Earl of Salisbury (this William's father) :

"In 1392 , [the 2nd Earl] sold the Lordship of the Isle of Man to William le Scrope of Bolton. He married Elizabeth, daughter of John de Mohun, 9th Lord de Mohun of Dunster. The two lived at Bisham Manor in Berkshire and had a son and two daughters. The son, Sir William Montacute, married Lady Elizabeth FitzAlan , daughter of Richard Fitzalan, 11th Earl of Arundel , but was killed in a tournament in 1383, leaving no children. When the elder William Montacute died in 1397 the earldom was inherited by his nephew John Montacute, 3rd Earl of Salisbury . One of William's sisters, Philippa (d. January 5, 1382), married Roger Mortimer, 2nd Earl of March ."

  Death Notes:

Killed in a tournament (per Wikipedia)

William married Elizabeth FitzAlan d'Arundelle, daughter of Sir Richard FitzAlan 11th Earl of Arundel & 10th Earl of Surrey and Elizabeth de Bohun Countess of Arundel. (Elizabeth FitzAlan d'Arundelle was born on 8 Jul 1379 in Derbyshire, England and died on 8 Jul 1425 in Hoveringham, England.)